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Journal Cover Reactive and Functional Polymers
  [SJR: 0.8]   [H-I: 72]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1381-5148
   Published by Elsevier Homepage  [3038 journals]
  • Development of novel antimicrobial films based on poly(lactic acid) and
           essential oils
    • Authors: Marwa Yahyaoui; Oihana Gordobil; René Herrera Díaz; Manef Abderrabba; Jalel Labidi
      Pages: 1 - 8
      Abstract: Publication date: December 2016
      Source:Reactive and Functional Polymers, Volume 109
      Author(s): Marwa Yahyaoui, Oihana Gordobil, René Herrera Díaz, Manef Abderrabba, Jalel Labidi
      Novel biocomposite films based on poly (lactic acid) (PLA) were prepared by incorporating essential oils as active additive with different concentrations (0.5, 1.5, 2 and 5%). Different types of essential oils from Rosemary, Myrtle and Thyme were used. The optical, thermal, mechanical, water vapour permeability and antifungal properties of all films was carried out. The analysis of essential oils by GC-MS showed the presence of terpene and phenolic compounds that are the most important compounds in essential oils. The addition of different essential oils does not affect the colour change of the films significantly. Thermal degradation of studied films showed a small decrease in the initial degradation temperature when the concentration of essential oil increased, however maximum degradation temperature was similar. Thermal analysis by differential scanning calorimetric (DSC) showed that PLA films containing 5% of commercial essential oils of myrtle and thyme could reduce the polymer chain to crystallize. The mechanical properties are improved by the incorporation of essential oils in the PLA matrix. The effect of commercial essential oil of myrtle in the transfer of humidity from the atmosphere to food is low compared with those containing the commercial essential oils of rosemary and thyme. Finally, the addition of 1.5% commercial thyme and 5% natural myrtle increase significantly the antifungal activity against Aspergillus.niger sp.

      PubDate: 2016-09-21T03:29:31Z
      DOI: 10.1016/j.reactfunctpolym.2016.09.001
      Issue No: Vol. 109 (2016)
       
  • Highly conductive and hydrated PEG-based hydrogels for the potential
           application of a tissue engineering scaffold
    • Authors: Yong Seok Kim; Kanghee Cho; Hyun Jong Lee; Sooho Chang; Hyungsuk Lee; Jung Hyun Kim; Won-Gun Koh
      Pages: 15 - 22
      Abstract: Publication date: December 2016
      Source:Reactive and Functional Polymers, Volume 109
      Author(s): Yong Seok Kim, Kanghee Cho, Hyun Jong Lee, Sooho Chang, Hyungsuk Lee, Jung Hyun Kim, Won-Gun Koh
      A PEG-based hydrogel with a high conductivity and water content was synthesized using a two-step sequential polymerization process by in-situ polymerizing poly(3,4-ethylenedioxythiophene) (PEDOT) within poly(4-styrenesulfonic acid) (PSS)-containing poly(ethylene glycol) diacrylate (PEG-DA) hydrogel matrix. A small amount of diluted sulfuric acid (H2SO4) was added as an accelerator to increase the conductivity via reduced polymerization time. Among the various molecular weights (MW) of PEG, PEG-DA with MW 3400 was used for first hydrogel due to its mechanical property and water content. Incorporation of PSS within the PEG hydrogel facilitated the in-situ synthesis of PEDOT within the hydrogel, producing a hydrogel with a higher conductivity, which was further enhanced by H2SO4 treatment. The resultant semi-interpenetrating network hydrogel scaffolds were shown to consist of up to more than 80wt% of water with a compressive modulus of 21kPa and an electrical conductivity of 1.69×10−2 Scm−1. The surface of the resultant conductive hydrogel could be modified via photochemical fixation for cell adhesion with negligible conductivity change. In vitro studies using electro-responsive H9C2 myocytes showed that the developed hydrogels not only did not exhibit any cytotoxicity but also supported cell adhesion and proliferation. This work demonstrates that the architectural design of the conductive hydrogel scaffolds and growth mechanism of PEDOT in the hydrogel platform play a pivotal role in determining the properties of the resulting conductive hydrogel. The attractive performance of these hybrid hydrogels will open a new approach for the further research on electrically conductive tissue engineering scaffolds.

      PubDate: 2016-10-02T04:32:45Z
      DOI: 10.1016/j.reactfunctpolym.2016.09.003
      Issue No: Vol. 109 (2016)
       
  • Hydroxyl-enhanced magnetic chitosan microbeads for boron adsorption:
           Parameter optimization and selectivity in saline water
    • Authors: Akeem Adeyemi Oladipo; Mustafa Gazi
      Pages: 23 - 32
      Abstract: Publication date: Available online 29 September 2016
      Source:Reactive and Functional Polymers
      Author(s): Akeem Adeyemi Oladipo, Mustafa Gazi
      Hydroxyl-enhanced materials are considered promising for boron adsorption. But, the use of these materials is hindered by issues of selectivity and separation notably in the presence of co-existing ions. Therefore, magnetic chitosan-based microbeads (MC) were synthesized and functionalized with a glycidol to produce boron-selective adsorbent (MCG). The resulting multi-hydroxyl microbeads were found to be a better substitute to the existing boron adsorbents. The adsorbents were characterized by scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The BET surface area and vibrating sample magnetometry analyzes confirmed that the functionalized beads had a saturation magnetization, surface area, pore size, and diameter of 46.53Am2/kg, 598m2/g, 2.9nm and ∼150–400μm respectively. Under optimized condition, the MCG showed high adsorption affinity and remarkable selectivity towards boron in the presence of co-existing metal ions (Cu2+, Fe3+, and Ni2+) and salts of Mg2+, Ca2+, Na+ and K+ ions. MCG has 128.5mg/g of boron loading capacity within the first 100min, which is relatively higher than reported values. The spent beads were separated easily from the suspensions by an external magnet and reuse repeatedly.

      PubDate: 2016-10-02T04:32:45Z
      DOI: 10.1016/j.reactfunctpolym.2016.09.005
      Issue No: Vol. 109 (2016)
       
  • Synthesis of novel monolithic cartridges with specific recognition sites
           for extraction of melamine
    • Authors: Evin Mine Dursun; Recep Üzek; Nilay Bereli; Serap Şenel; Adil Denizli
      Pages: 33 - 41
      Abstract: Publication date: Available online 23 September 2016
      Source:Reactive and Functional Polymers
      Author(s): Evin Mine Dursun, Recep Üzek, Nilay Bereli, Serap Şenel, Adil Denizli
      Synthesis of melamine (ME) imprinted polymeric sorbent for use as solid phase extraction adsorbent was targeted and the benefits of the synthesis in the monolith format were combined with imprinting technology advantages. Melamine as template and 2-vinylimidazole-Cu2+ as complexing agent were used as the first time for pre-complex formation, followed by the preparation of monolith by bulk polymerization method in the presence of ethyleneglycol dimethacrylate as crosslinker, azobisisobutyronitrile as initiator, and ethyl alcohol as solvent for a duration of 4h at 80°C. 1.0M NaOH solution was used as a desorption agent to remove template. Non-imprinted monolith (NIP) were synthesized as a control without template in same receipt. The monolith samples were characterized by Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), elementary analysis, and Branauer- Emmett- Teller (BET) studies. Melamine adsorption from aqueous solution was studied in continuous mode, and some parameters such as pH, temperature, concentration and flow-rate were optimized for melamine adsorption. The maximum adsorption capacities were determined as 147.9mg/g for imprinted polymer (MIP), 82.0mg/g for non-imprinted polymer (NIP) and 4.0mg/g for polymer without pre-complex (E) at 25°C, and pH5.0 with 500ppm melamine initial concentration for 1.0mL/min flow-rate. In addition to interaction characterized by metal coordination bond formation, non- covalent interactions were responsible for melamine adsorption. No significant change in adsorption performance was recorded after 10 consecutive adsorption-desorption cycles. Kinetic analysis indicated compliance with pseudo-second order kinetics. The Freundlich isotherm was found suitable for description of the process. Cyanuric acid (CY), aniline (AN), and phenol (PH) were used as competing agents in selectivity studies, and relative selectivity coefficients were calculated (k'CY =4.45; k'AN =7.08; k'PH =3.98). The performance of melamine imprinted polymeric monolith (MIP) as solid-phase extraction adsorbent for extraction of melamine from milk samples was investigated and the recovery of melamine in spiked milk samples was 97.6% with the relative standard deviation (RSD) (8.1%).

      PubDate: 2016-09-26T04:08:54Z
      DOI: 10.1016/j.reactfunctpolym.2016.09.002
      Issue No: Vol. 109 (2016)
       
  • Preparation and fracture process of high strength hyaluronic acid
           hydrogels cross-linked by ethylene glycol diglycidyl ether
    • Authors: Burak Tavsanli; Oguz Okay
      Pages: 42 - 51
      Abstract: Publication date: Available online 6 October 2016
      Source:Reactive and Functional Polymers
      Author(s): Burak Tavsanli, Oguz Okay
      We present a synthetic strategy to produce high-strength hydrogels based on hyaluronic acid, a unique biomacromolecule with distinctive biological functions. The hydrogels were prepared using a two-step procedure. In the first step, hyaluronic acid (HA) was chemically cross-linked in aqueous solutions using ethylene glycol diglycidyl ether (EGDE) under various experimental conditions. EGDE-cross-linked HA hydrogels containing 97–99% water were fragile, and ruptured when compressed to 25–51% strain under 0.02–0.15MPa stresses. By applying the double-network approach in the second step, we were able to generate high strength HA/ poly(N,N-dimethylacrylamide) double-network hydrogels containing 84–94% water. Tuning the ratio of the network components could result in hydrogels exhibiting a compressive modulus of 0.9MPa that sustain 19.4MPa compressive stresses, which are much larger than those reported before for the hydrogels derived from the methacrylated HA macromers. Thus, the hydrogels presented here are promising materials to make use the characteristics of HA in stress-bearing biomedical applications. Cyclic mechanical tests show irreversible stress-strain curves with a large hysteresis indicating that elastically effective cross-links of HA first-network are irreversibly destroyed under load by dissipating energy. This internal fracture of HA network together with the high mass ratio of the second to the first-network components are responsible for the extraordinary mechanical properties of the hydrogels.

      PubDate: 2016-10-09T23:03:17Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.001
      Issue No: Vol. 109 (2016)
       
  • Highly branched polyethylenes as lubricant viscosity and friction
           modifiers
    • Authors: Joshua W. Robinson; Yan Zhou; Jun Qu; J. Timothy Bays; Lelia Cosimbescu
      Pages: 52 - 55
      Abstract: Publication date: Available online 8 October 2016
      Source:Reactive and Functional Polymers
      Author(s): Joshua W. Robinson, Yan Zhou, Jun Qu, J. Timothy Bays, Lelia Cosimbescu
      A series of highly branched polyethylenes (BPE) were prepared and evaluated in a Group I base oil as potential viscosity and friction modifiers. The performance of these BPEs supports the expected dual functionality. Changes in polarity, topology, and molecular weight of the BPEs showed significant effects on the lubricants' performance with respect to viscosity index and friction reduction. This study provides scientific insights into polymer design for future lubricant development activities.

      PubDate: 2016-10-09T23:03:17Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.003
      Issue No: Vol. 109 (2016)
       
  • The preparation and study of poly(vinylidene
           fluoride)/ultrahigh-molecular-weight polyethylene/SiO2 hollow fiber
           membrane with network enhanced structure
    • Authors: Nana Li; Feng Liu; Qingchen Lu; Yanli Shi; Changfa Xiao; Bowen Cheng
      Pages: 64 - 69
      Abstract: Publication date: December 2016
      Source:Reactive and Functional Polymers, Volume 109
      Author(s): Nana Li, Feng Liu, Qingchen Lu, Yanli Shi, Changfa Xiao, Bowen Cheng
      The compatibility of poly(vinylidene fluoride) (PVDF)/ultrahigh-molecular-weight polyethylene (UHMWPE) blends is studied by methods of solubility parameter and melting temperature decreasing. And the melting behavior and crystallization properties are researched by rheological properties testing and differential scanning calorimetry. Based on these, PVDF/UHMWPE/SiO2 blends hollow fiber hydrophobic membranes with network enhanced structure and porous structure are prepared by thermally induced phase separation (TIPS) and screw extrusion spinning method, with mineral oil as diluent. Then the membrane morphology is observed by scanning electron microscopy (SEM). Finally, properties of membrane are studied by porosity and pore diameter analysis, stretching experiment and contact angle measurement. The results show that the porous structure is improved by interface pores formed due to the poor compatibility between PVDF and UHMWPE. Moreover, the network enhanced structure with rough surface is built by PVDF spherical micro-particles and SiO2 inorganic particles connected with UHMWPE micro-fibrils. The structure can strengthen mechanical properties of membrane.

      PubDate: 2016-10-30T21:45:44Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.005
      Issue No: Vol. 109 (2016)
       
  • Preparation of multifunctional conductive polymers with-C=N-conjugated
           system and amino groups and application as active coating additives
    • Authors: Xiaodong Quan; Jixiao Wang; Song Zhao; Zhi Wang; Shichang Wang
      Pages: 79 - 87
      Abstract: Publication date: December 2016
      Source:Reactive and Functional Polymers, Volume 109
      Author(s): Xiaodong Quan, Jixiao Wang, Song Zhao, Zhi Wang, Shichang Wang
      Multifunctional conductive polymers with CN conjugated system and functional groups were prepared by polycondensation of carbamide at high temperature under elevated pressure. The corresponding molecular structures of these polycondensation of carbamide products (PCA) were proposed according to the analysis of elemental analysis, FT-IR spectra, UV–Visible absorption spectra and X-ray photoelectron spectroscopy. The morphology of the obtained products can be tuned by controlling the synthesis conditions such as temperature, pressure and catalyst used in the synthesis process. X-ray diffraction (XRD) patterns confirmed the existence of relatively ordered crystal structures for these polymers. Corrosion protection performance of as-prepared coatings with PCAs was investigated based on NaCl solution immersion test. The results indicated that PCA-2 nanoparticles can improve the protection performance for metals by increasing the adhesion strength of the epoxy coatings and acting as crosslinking points to form a dense film.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.014
      Issue No: Vol. 109 (2016)
       
  • Editorial
    • Authors: Guey-Sheng Liou; Wen-Chang Chen; Toyoji Kakuchi
      First page: 1
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Guey-Sheng Liou, Wen-Chang Chen, Toyoji Kakuchi


      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.006
      Issue No: Vol. 108 (2016)
       
  • Highly transparent polyimide hybrids for optoelectronic applications
    • Authors: Chia-Liang Tsai; Hung-Ju Yen; Guey-Sheng Liou
      Pages: 2 - 30
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Chia-Liang Tsai, Hung-Ju Yen, Guey-Sheng Liou
      Polyimides comprising high polarized moieties and electron-withdrawing groups usually exhibit high refractive index and good transparency with great potential for optoelectronic devices. Particularly, the incorporation of hydroxyl groups on the backbones of polyimides is an important strategy to enhance the solubility and provide reactive sites for organic-inorganic bonding. Composites prepared from organic polymer binder and inorganic fillers have recently attracted considerable interests due to their enhanced mechanical, thermal, optical and electrical properties compared to the corresponding polymer or inorganic component. Moreover, the inorganic components in hybrid films can also serve as electron acceptors for stabilizing the charge transfer complex thus result in electrically programmable digital memory properties. In addition, the high performance polyimides can further served as substrate and protector for the AgNWs-polyimide conductive hybrid films, exhibiting good adhesive property, high bendability, and excellent thermal stability. Owing to the high glass transition temperature (T g) of polyimides, the resulted AgNWs-polyimide electrode can maintain its conducting performance at high temperature operation. Thus, the hybrid electrode provided extremely high potential to operate at harsh working environment or further post processing. By the excellent combination of transparent polyimides and inorganic materials, the resulting polyimide hybrids showing promising potential are indispensable to optical and electrical applications.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.021
      Issue No: Vol. 108 (2016)
       
  • High-performance non-volatile transistor memory devices using
           charge-transfer supramolecular electrets
    • Authors: Chen-Tsyr Lo; Hung-Chin Wu; Wen-Ya Lee; Wen-Chang Chen
      Pages: 31 - 38
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Chen-Tsyr Lo, Hung-Chin Wu, Wen-Ya Lee, Wen-Chang Chen
      We demonstrated high performance non-volatile pentacene based OFET memory devices using charge-transfer (CT) supramolecules of poly(4-vinylpyridine) (P4VP) with two different chromophores, 3-(dicyanomethylidene)indan-1-one (1CN-IN) and 1,3-bis(dicyanomethylidene)indan (2CN-IN), respectively. The intermolecular CT interaction effectively introduced the chromophores as charge trapping sites into the P4VP matrix, leading to a controllable flash-type memory behavior. The electron-trapping ability of the supramolecular electrets was increased with enhancing the chromophore composition in the supramolecules. The experimental molar ratio x of chromophores binding to the repeating unit of P4VP, however, was limited to 0.30 for P4VP(1CN-IN)x or 0.45 for P4VP(2CN-IN)x. The 2CN-IN with one more electron-withdrawing dicyanomethylene group, compared to 1CN-IN, provided a better electron-trapping ability and thus obtained a larger memory window. The device based on P4VP(2CN-IN)0.30 electret exhibited the largest memory window (79V) with the excellent retention ability of up to 107 s and endurance of over 100cycles. The study revealed that the CT supramolecular electret could be as a facile and simple approach for future organic memory device applications.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.03.023
      Issue No: Vol. 108 (2016)
       
  • Low voltage operation of non-volatile flexible OFET memory devices using
           high-k P(VDF-TrFE) gate dielectric and polyimide charge storage layer
    • Authors: Mao-Shen Lu; Hung-Chin Wu; Yu-Wei Lin; Mitsuru Ueda; Wen-Chang Chen
      Pages: 39 - 46
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Mao-Shen Lu, Hung-Chin Wu, Yu-Wei Lin, Mitsuru Ueda, Wen-Chang Chen
      Flexible OFET memory devices of semiconducting poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) on PEN substrates were fabricated and characterized using a high-k poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) gate dielectric combined with donor–acceptor polyimide electrets of (poly[2,5-bis(4-aminophenylenesulfanyl)selenophene-hexafluoroisopropylidene diphthalimide] (APSP-6FDA) or poly[2,5-bis(4-aminophenylenesulfanyl)thiophene-hexafluoroisopropylidenediphthalimide] (APST-6FDA)). All the polymer thin films, including gate dielectric, charge storage, and semiconducting layer, possessed a smooth surface to form good contact adhesion between each layer, as confirmed by atomic force microscopy. The flexible OFET device could be operated using low gate voltage (<15V) because of the high dielectric constant of P(VDF-TrFE). In addition, the OFET memory devices exhibited a reversible non-volatile behavior with a memory window over 10V and an on/off memory ratio of 103. The data storage characteristic was mainly attributed to the charge trapping in polyimide layer under a positive or negative gate bias. The studied flexible memories, moreover, exhibited stable electrical parameters, such as charge carrier mobility, threshold voltage change, and memory window, under a bending radius of 10mm with 1000 repeating cycles, resulting in reproducible and reliable device characteristics. The experimental results indicated that a low-voltage operated non-volatile flexible OFET memory device could be simply integrated using all polymer components, including gate dielectric, charge storage electret, and semiconductor.
      Graphical abstract image

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.001
      Issue No: Vol. 108 (2016)
       
  • Tetraphenylthiophene-terminated poly(acrylic acid) as pH- and bio-sensors
           by the aggregation-induced emission property
    • Authors: Deng-Jie Yang; Li-Yang Lin; Po-Chiao Huang; Jhen-Yan Gao; Jin-Long Hong
      Pages: 47 - 53
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Deng-Jie Yang, Li-Yang Lin, Po-Chiao Huang, Jhen-Yan Gao, Jin-Long Hong
      Amphiphilic poly(acrylic acid) terminated with tetraphenylthiophene (TP) was prepared by atom transfer radical polymerization (ATRP) of t-butyl acrylate monomer, initiated by amino-functionalized TP, and the following by acid-catalyzed hydrolysis. With the hydrophobic TP terminal, a fluorophore with aggregation-induced emission (AIE) property, and the hydrophilic polymeric chain, the resulting polymer of TP-PAA is amphiphilic and self-assembled, through preferable hydrogen bond interactions among the carboxylic acid pedants, in water to form aggregates with strong AIE-related emission. The convenient dispersion of TP-PAA aggregates in water facilitated its applications as fluorescent sensor for pH value and for the natural protein of bovine serum albumin (BSA). Fluorescence variations in term of aggregation level of the TP terminals in different environments will be discussed in this study.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.05.004
      Issue No: Vol. 108 (2016)
       
  • Triphenylamine-based redox-active aramids with 1-piperidinyl substituent
           as an auxiliary donor: Enhanced electrochemical stability and
           electrochromic performance
    • Authors: Sheng-Huei Hsiao; Ying-Hsiu Hsiao; Yu-Ruei Kung; Chyi-Ming Leu; Tzong-Ming Lee
      Pages: 54 - 62
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Sheng-Huei Hsiao, Ying-Hsiu Hsiao, Yu-Ruei Kung, Chyi-Ming Leu, Tzong-Ming Lee
      A new triphenylamine-based diamine monomer 4,4′-diamino-4″-(1-piperidinyl)triphenylamine was synthesized and polymerized with various aromatic dicarboxylic acids via the phosphorylation polyamidation technique leading to a series of redox-active aromatic polyamides (aramids). All the aramids exhibit good solubility in many organic solvents and can be solution-cast into flexible and strong films with high thermal stability. Cyclic voltammograms of the polymer films on the indium-tin oxide (ITO)-coated glass substrate exhibit a pair of well-defined and reversible oxidation waves with very low onset potentials of 0.27–0.35V (vs. Ag/AgCl) in acetonitrile solution, with a strong color change from colorless neutral form to green and deep blue oxidized forms in the range of 0.75–1.20V. The optical transmittance change (Δ%T) at 636nm between the neutral state and the fully oxidized state is up to 83%.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.03.020
      Issue No: Vol. 108 (2016)
       
  • New high-solubility aromatic polyesters with pendent phenothiazine:
           Synthesis, electrochromic and optoelectronic properties
    • Authors: Xiaochuan Ma; Haijun Niu; Wanan Cai; Tiandi Xiao; Cheng Wang; Xuduo Bai; Yanhong Zhang; Wen Wang
      Pages: 63 - 70
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Xiaochuan Ma, Haijun Niu, Wanan Cai, Tiandi Xiao, Cheng Wang, Xuduo Bai, Yanhong Zhang, Wen Wang
      A series of aromatic polyesters were synthesized from dicarboxylic acids, containing pendent triphenylamine substituted with phenothiazine, and five different kinds of bisphenols. The aromatic polyesters exhibited good solubility in organic solvents due to bulky propeller-like triphenylamine and butterfly-like conformation of phenothiazine, which were convenient for the polymers to fabricate films and devices by spin- or inject-coating. They also revealed good thermal stability with 10% weight lost at 420°C. In addition, the polymer showed a strong yellow fluorescence at 522nm in the THF solution and irregular solvatochromic characteristic in polar solvents. Furthermore, their films had well reversible redox process in the range of 0–1.2V with the color changing from colorless neutral to red in the range of 0.80–0.85V. The calculated HOMO and LUMO energy levels of polyesters demonstrated their potential application as photoelectrical materials.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.05.005
      Issue No: Vol. 108 (2016)
       
  • Synthesis and properties of highly organosoluble and low dielectric
           constant polyimides containing non-polar bulky triphenyl methane moiety
    • Authors: Wenxin Chen; Zhuxin Zhou; Tingting Yang; Runxin Bei; Yi Zhang; Siwei Liu; Zhenguo Chi; Xudong Chen; Jiarui Xu
      Pages: 71 - 77
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Wenxin Chen, Zhuxin Zhou, Tingting Yang, Runxin Bei, Yi Zhang, Siwei Liu, Zhenguo Chi, Xudong Chen, Jiarui Xu
      Novel fluorinated aromatic polyimides were prepared by the conventional two-step imidization of 4.4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and diamines (TriPMPDA and TriPMMDA) bearing triphenyl methane moiety. Both of the flexible and tough polyimide films exhibited an intrinsic low dielectric constant (low-k) values of 2.56 and 2.33 at the frequency of 10kHz, respectively, due to the introduction of the bulky triphenyl methane side groups and the tortuous backbone structures. In addition, they showed light color, high thermal stability, moderate mechanical property, and more importantly, excellent solubility in common organic solvents (even completely dissolved in dichloromethane and chloroform). Thus, both of the functional polyimides possessed attractive potential applications in the field of high performance flexible polymer interlayer materials.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.011
      Issue No: Vol. 108 (2016)
       
  • Synthesis of highly transparent poly(amide–imide)s based on trimellitic
           acid and dependence of thermal properties on monomer sequence
    • Authors: Yutaro Kobayashi; Yumi Fujiwara; Takuya Kitaoka; Yoshiyuki Oishi; Yuji Shibasaki
      Pages: 78 - 85
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Yutaro Kobayashi, Yumi Fujiwara, Takuya Kitaoka, Yoshiyuki Oishi, Yuji Shibasaki
      Transparent, thermally stable, and semiaromatic poly(amide–imide)s were prepared from hydrogenated trimellitic anhydride chloride (h-TAC) with various aromatic diamines. The dependence of thermostability on the monomer sequence and terminal group was investigated. Thermogravimetric/differential thermal analysis (TG/DTA) was performed to evaluate the thermostabilities, which were found to be primarily affected by the monomer sequence in the polymer units. The 5% weight loss temperature (Td5) in N2, glass transition temperature (T g ), and cutoff wavelength of the ultraviolet–visible (UV–Vis) spectrum (λcut) of the semiaromatic poly(amide–imide)s are 422–456°C, 131–274°C, and 293–321nm, respectively, while those of wholly aromatic poly(amide–imide)s are 454–480°C, 169–287°C, and 415nm, respectively.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.016
      Issue No: Vol. 108 (2016)
       
  • Dendrons with urea/malonamide linkages for gate insulators of n-channel
           organic thin film transistors
    • Authors: Yu-Yi Hsu; Shih-Chieh Yeh; Shih-Hsun Lin; Chin-Ti Chen; Shih-Huang Tung; Ru-Jong Jeng
      Pages: 86 - 93
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Yu-Yi Hsu, Shih-Chieh Yeh, Shih-Hsun Lin, Chin-Ti Chen, Shih-Huang Tung, Ru-Jong Jeng
      A series of urea/malonamide dendritic molecules were prepared as gate insulators for organic thin film transistors (OTFTs). This series of molecules with different degrees of branching possess peripheral stearyl groups are dendrons generation 0.5 (G0.5), generation 1 (G1), generation 1.5 (G1.5), generation 2 (G2) and generation 2.5 (G2.5). In addition, two types of tetracarboxylic diimide derivatives, i.e. perylene diimide (PDI) and naphthalene diimide (NDI) with two different chain lengths of fluorinated alkyl end groups were prepared as semiconductors for OTFTs such as NDI-C4F7, NDI-C7F9, PDI-C4F7 and PDI-C7F9. The n-channel types of OTFTs were fabricated by spin-coating the gate insulators on Si/SiO2 substrates, and then depositing the semiconducting layers in vacuum without heating the substrate. Silver was used as contact electrodes for source and drain. The performance of OTFTs with dendrons as gate insulators were better than that of OTFTs modified by octadecyltrichlorosilane (ODTS). Moreover, the threshold voltages (V ths) of OTFTs shifted from positive voltage to negative voltage as the device was incorporated with higher generation of dendrons. This is because of different dielectric constants or surface energies between the interface of gate insulator and semiconducting layer. Among all samples in this study, the n-channel OTFT comprising PDI-C4F7 and G1.5 exhibited the best performance. In addition, an enhanced electron mobility and I on/I off ratio measured under ambient condition were 4.71×10−4 cm2 V−1 s−1 and 7.7×103, respectively. Apart from that, the influence of semiconducting molecular packing order on dendron gate insulator layers was investigated by grazing-incidence wide-angle X-ray scattering (GIWAXS) and atomic force microscopy (AFM). Furthermore, pentacene-based p-channel OTFTs with G1.5 gate insulator also exhibited the highest performance. These OTFTs achieved 0.1cm2 V−1 s−1 and 6.3×104 for mobility (μ) and I on/I off ratio, respectively.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.05.008
      Issue No: Vol. 108 (2016)
       
  • Self-organization and phase transformation of all π-conjugated diblock
           copolymers and its applications in organic solar cells
    • Authors: Ching Shen; Yi-Huan Lee; Yu-Ping Lee; Chi-Ju Chiang; Fan-Kai Wei; Chia-Hung Wu; Kuo-Chang Kau; Hung-Wei Liu; Chih-Chen Hsieh; Leeyih Wang; Chi-An Dai
      Pages: 94 - 102
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Ching Shen, Yi-Huan Lee, Yu-Ping Lee, Chi-Ju Chiang, Fan-Kai Wei, Chia-Hung Wu, Kuo-Chang Kau, Hung-Wei Liu, Chih-Chen Hsieh, Leeyih Wang, Chi-An Dai
      In this study, we report on the synthesis and self-assembling behavior of a series of monodisperse all π-conjugated poly(2,5-dihexyloxyp-phenylene)-block-(3-hexylthiophene) (PPP-P3HT) block copolymer system and construct its phase diagram that exhibits diverse nanostructures of predominant PPP nanofibers, PPP-P3HT lamellae, broken lamellae and predominant P3HT nanofibers as a function of the copolymer composition. An order-to-disorder phase transition is also observed for the copolymers at a temperature above the melting point of the predominant blocks, indicating the rod-rod interaction between the corresponding π-conjugated chains plays a key role in the formation and the stabilization of the observed nanostructures. In particular, we have also found that the incorporation of PPP segments to P3HT to form nanofibrillar structure significantly enhance the self-organization behavior of the P3HT in the copolymer. The improvements in crystallinity and mobility for the copolymers therefore substantially enhance their solar cell performance. The use of this novel material with diverse nanostructures provides a new strategy to enhance photovoltaic performance and shows the potential for use in future optoelectronic applications.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.06.007
      Issue No: Vol. 108 (2016)
       
  • Poly(ionic liquid) prepared by photopolymerization of ionic liquid
           
    • Authors: Shen-Mei Chen; Tzong-Liu Wang; Pei-Yu Chang; Chien-Hsin Yang; Yi-Chao Lee
      Pages: 103 - 112
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Shen-Mei Chen, Tzong-Liu Wang, Pei-Yu Chang, Chien-Hsin Yang, Yi-Chao Lee
      Vinylimidazolium-typed poly(ionic liquids) (PILs) are prepared by photo-polymerization of ionic liquid monomers. Vinylimidazolium-based ionic liquid monomers with C4 and C8 alkyl tail length were synthesized via quaternization of 1-vinylimidazole with corresponding n-alkyl bromides. Polymerization was conducted at a 3wt.% of photoinitiators in these monomers using illumination of 36W LED light. In the same procedure, preparation of cross-linked PILs was performed in the presence of 15mol% of divinylimidazolium-based cross-linker. These PILs are characterized by using chemical structure, physical characteristics, and electrical conductivity. Electrical conductivity of C4-based PILs is greater than that of C8-based PILs, whereas linear PILs are higher than crosslinked PILs. Crosslinked PILs have higher glass transition and thermal decomposition temperatures as compared linear PILs. PILs consist of the repeating units of anion and cation pair. Its nature has moderate electronic conductivity, which is suitable use in gel-type or quasi-solid-state dye-sensitized solar cells (DSSCs). The linear PILs were incorporated in DSSCs obtaining an efficient quasi-solid-state cell to solve the leakage of liquid electrolyte in a liquid-type DSSC.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.06.006
      Issue No: Vol. 108 (2016)
       
  • Synthesis, characterization, and photovoltaic applications of
           donor-acceptor alternating and random copolymers based on a ladder-type
           nonacyclic structure
    • Authors: Wei-Wei Liang; Yu-Shun Lin; Yu-Ying Lai; Yen-Ju Cheng
      Pages: 113 - 121
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Wei-Wei Liang, Yu-Shun Lin, Yu-Ying Lai, Yen-Ju Cheng
      A nonacylic building block TPTPT with the alternate thiophene and benzene subunits fastened by four bridging methylene groups was connected with various acceptors including diphenylquinoxaline (QX), thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD), thieno[3,4-b]thiophene (TT) to afford donor-acceptor (D-A) alternating copolymers - PTPTPTQX, PTPTPTTPD, and PTPTPTTT and random copolymers - PTPTPTQX11, PTPTPTQX12, PTPTPTTPD11, PTPTPTTPD12, PTPTPTTT11, and PTPTPTTT12. The thermal, optical, and electrochemical properties of these copolymers were measured and compared. The random copolymers all have higher glass transition temperature (T g ) than the corresponding alternating copolymers. ONIOM (our own n-layered integrated molecular orbital and molecular mechanics) calculations suggest that the increase of planarity in the random copolymers arises from the introduction of thiophene units intercalating between donor and acceptor moieties. Bulk heterojunction (BHJ) polymer solar cells (PSCs) were fabricated on the basis of ITO/PEDOT:PSS/polymer:PC71BM/Ca/Al device configuration. When the acceptor is QX or TPD, the resultant alternating copolymers performed superior than the random counterparts. When the acceptor is TT, the high content of TT seems to be harmful to the device efficiency, which may relate with the strong quinoidal character of the TT unit. Overall, for the TPTPT core structure, in the used acceptors, the alternating-copolymer arrangement appears to be a better construction manner for the purpose of BHJ PSC applications.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.002
      Issue No: Vol. 108 (2016)
       
  • Synthesis of soluble polybenzimidazoles for high-temperature proton
           exchange membrane fuel cell (PEMFC) applications
    • Authors: Jyh-Chien Chen; Ping-Yen Chen; Shih-Wei Lee; Geng-Lun Liou; Chun-Jung Chen; Yi-Hsin Lan; Kuei-Hsien Chen
      Pages: 122 - 129
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Jyh-Chien Chen, Ping-Yen Chen, Shih-Wei Lee, Geng-Lun Liou, Chun-Jung Chen, Yi-Hsin Lan, Kuei-Hsien Chen
      Three new diacids, 3, 5 and 7, were successfully synthesized by bromination, esterification, Suzuki coupling and hydrolysis from 4,4′-oxybis(benzoic acid). These diacids containing bulky bromide, phenyl and trifluoromethyl-substituted phenyl substituents, respectively. Polybenzimidazoles P1–P3, derived from these diacids and 3,3′-diaminobenzidine, were prepared in Eaton's reagent at 145°C. They were soluble in NMP, DMAc and DMF. It indicates the effectiveness of introducing bulky substituents in improving the solubility of PBIs in polar aprotic solvents. P1–P3 also exhibited good thermal stability without significant degradation up to 400°C and high glass transition temperatures (>305°C). In addition, their oxidative stability, phosphoric acid doping levels, mechanical properties, dimensional stability after doping and proton conductivity were evaluated and compared with those of commercially available m-PBI. The proton conductivities of P1–P3 were in the range of 1.3–11.0×10−2 S/cm at 160°C. The fuel cells based on P2 containing phenyl substituents exhibited much better performance than the one based on m-PBI, with an open circuit voltage of 0.96V and a peak power density of 781mW/cm2 at 160°C.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.05.006
      Issue No: Vol. 108 (2016)
       
  • Controllable electrical performance of spray-coated semiconducting small
           molecule/insulating polymer blend thin film for organic field effect
           transistors application
    • Authors: Li-Hui Chou; Wei-Chieh Chang; Guan-Yu He; Yu-Cheng Chiu; Cheng-Liang Liu
      Pages: 130 - 136
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Li-Hui Chou, Wei-Chieh Chang, Guan-Yu He, Yu-Cheng Chiu, Cheng-Liang Liu
      A systematic study on solution content and solvent effect of spray-coated 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-PEN)/poly(α-methylstyrene) (PαMS) semiconducting blends for organic field effect transistors (OFETs) application was investigated based on different concentrations (10, 15 and 20mgml−1), different compositions (TIPS-PEN/PαMS of 7/3, 5/5 and 3/7) and three different solvents, toluene (TOL), chlorobenzene (CB), and 1,2,3,4-tetrahydronaphthalene (THN). Polarized optical microscopy (POM), atomic force microscopy (AFM) and grazing-incidence X-ray diffraction (GIXRD) were used to evaluate the film morphology and chain orientation. The blend film can contribute to large coverage of TIPS-PEN carrier pathway across the OFETs channel if higher TIPS-PEN composition with suitable total blend concentration was introduced in the blend. Besides, the blend film processed from high boiling point THN can reduce the rate of evaporation which provides more time for TIPS-PEN migration to form a large grain of TIPS-PEN crystal. The resulting OFETs based on spray-coated from TIPS/PαMS (7/3) blend solution in THN exhibit maximum mobility of 3.23×10−1 cm2 V−1 s−1 and ON/OFF ratio of >104.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.04.017
      Issue No: Vol. 108 (2016)
       
  • Pyrene or rhodamine derivative–modified surfaces of electrospun
           nanofibrous chemosensors for colorimetric and fluorescent determination of
           Cu2+, Hg2+, and pH
    • Authors: Chia-Jung Cho; Shih-Tung Lu; Chi-Ching Kuo; Fang-Cheng Liang; Bo-Yu Chen; Chien-Chia Chu
      Pages: 137 - 147
      Abstract: Publication date: November 2016
      Source:Reactive and Functional Polymers, Volume 108
      Author(s): Chia-Jung Cho, Shih-Tung Lu, Chi-Ching Kuo, Fang-Cheng Liang, Bo-Yu Chen, Chien-Chia Chu
      Novel fluorescent nanofibrous nonwoven-state sensors exhibiting high sensitivity to heavy metal ions were prepared from pyrene derivative (PyDAN2) or rhodamine B derivative (RhBN2)–modified poly(2-hydroxyethyl methacrylate-co-N-methylolacrylamide) (poly(HEMA-co-NMA)) electrospun (ES) nanofibers by employing a single-capillary spinneret. The HEMA moieties were designed to exhibit hydrophilic properties, and the NMA content substantially affected the stability of the ES nanofibers in water as well as enhanced their endurance in various organic solvents. PyDAN2 and RhBN2 grafted onto the cross-linked poly(HEMA-co-NMA) ES nanofibers through surface-initiated polymerization were denoted as Fiber-g-PyDAN2 and Fiber-g-RhBN2, respectively; they exhibited highly selective detection capabilities for copper (Cu2+) and mercury (Hg2+) ions/pH, respectively. The fluorescence emission colors of Fiber-g-PyDAN2 and Fiber-g-RhBN2 were initially nonfluorescent, but they transformed into strong fluorescence emissions with blue and orange-red colors when they detected Cu2+ and Hg2+/pH, respectively. These sensors have high reversibility because their on–off switchable fluorescence emissions cycled several times upon the sequential addition of Cu2+/Hg2+ and EDTA or acidic and alkaline media. The prepared chemosensors can be grafted onto ES nanofibrous membranes and can be used as “naked eye” sensors. They have potential applications in environmental sensing devices, especially in pollution sensors.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.05.019
      Issue No: Vol. 108 (2016)
       
  • Synthesis, self-assembly and pH sensitivity of PDEAEMA–PEG–PDEAEMA
           triblock copolymer micelles for drug delivery
    • Authors: Guiyou Wang; Lingmei Zhang
      Pages: 1 - 10
      Abstract: Publication date: Available online 3 August 2016
      Source:Reactive and Functional Polymers
      Author(s): Guiyou Wang, Lingmei Zhang
      In this study, well-defined double-hydrophilic triblock copolymers, consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(N,N-diethylamino-2-ethylmethacrylate) (PDEAEMA), were synthesized and characterized. The molecular weights of the copolymers were controllable. In the basic environments, the copolymers can self-assemble into the PDEAEMA core and PEG corona micelles in aqueous solution with an average size of 40–180nm. The low critical micelle concentration (CMC, about 10−3 mgmL−1) of copolymers investigated in pH7.4 aqueous solution confirmed the adequate thermodynamic stability of their self-assembly. As shown in the cytotoxicity assay, the copolymers have good biocompatibility. Doxorubicin (DOX) was encapsulated into the triblock copolymer micelles. The drug loading efficiency and entrapment efficiency values of DOX-loaded micelles reached 8.14% and 88.6%, respectively. The DOX release of the drug-loaded micelles depends on the pH values. These phenomena indicated that the double-hydrophilic PDEAEMA–PEG–PDEAEMA triblock copolymers have a potential application in the drug delivery.

      PubDate: 2016-08-05T16:07:34Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.001
      Issue No: Vol. 107 (2016)
       
  • Synthesis and Metal Complexation of Dual-functionalized Silsesquioxane
           Nanoparticles by Sequential Thiol–Epoxy Click and Esterification
           Reactions
    • Authors: Shun Shibasaki; Yusuke Sasaki; Kazuhiro Nakabayashi; Hideharu Mori
      Pages: 11 - 19
      Abstract: Publication date: Available online 5 August 2016
      Source:Reactive and Functional Polymers
      Author(s): Shun Shibasaki, Yusuke Sasaki, Kazuhiro Nakabayashi, Hideharu Mori
      Here, we demonstrate a convenient and robust method for fabricating a series of dual-functionalized silsesquioxane nanoparticles (SQ-NPs) using a thiol–epoxy click reaction and subsequent esterification. Epoxy-functionalized SQ-NP was initially prepared from commercially available (3-glycidyloxypropyl)triethoxysilane. A thiol compound, 2-mercaptopyridine, was used in the thiol–epoxy click reaction, and sulfur-containing acid chloride derivatives were used for subsequent functionalization via esterification. The resulting SQ-NPs have two chemically different groups on a single arm, which affords a high density of peripheral functional groups. The dual-functionalized SQ-NPs with the pyridine and thioether units led to the complexation with copper species, affording a stable Cu complex. This convenient synthetic approach provided dual-functionalized SQ-NPs with narrow size distributions (average particle diameter < 3 nm), reasonable molecular weights (M n = 3300–4200, M w/M n = 1.32–1.45), good solubility, relatively high refractive indices, and the ability to form characteristic metal complexes.

      PubDate: 2016-08-10T16:20:48Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.003
      Issue No: Vol. 107 (2016)
       
  • Synthesis of block copolymer with photo-decomposable polyurethane and its
           photo-initiated domino decomposition
    • Authors: Yoshihito Ishida; Yukie Takeda; Atsushi Kameyama
      Pages: 20 - 27
      Abstract: Publication date: Available online 16 August 2016
      Source:Reactive and Functional Polymers
      Author(s): Yoshihito Ishida, Yukie Takeda, Atsushi Kameyama
      A block copolymer consisting of a photo-decomposable polyurethane and poly(methyl methacrylate) (PMMA) was developed. The end-functionalized polyurethane (P2) was synthesized by polycondensation with the end-functionalization reagents. P2 possesses the photosensitive o-nitrobenzyl group and the 2-bromoisobutyryl group as the initiator of the atom transfer radical polymerization (ATRP). The block copolymer (P2-b-PMMA) was synthesized by the ATRP of methyl methacrylate (MMA) with P2 as the macroinitiator. The P2 block in P2-b-PMMA was decomposed by photo-irradiation at 365nm by the initiation of the photo-fries rearrangement of the urethane linkage and the subsequent domino reaction consistent with the elimination of the aza-quinone methide and decarboxylation. The photo-initiated decomposition of the P2 segment in the thin-film state was accomplished.

      PubDate: 2016-08-20T16:53:27Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.004
      Issue No: Vol. 107 (2016)
       
  • Preparation of pH-sensitive micelles from miktoarm star block copolymers
           by ATRP and their application as drug nanocarriers
    • Authors: Lu-mei Huang; Li-dong Li; Le Shang; Qing-han Zhou; Juan Lin
      Pages: 28 - 34
      Abstract: Publication date: Available online 18 August 2016
      Source:Reactive and Functional Polymers
      Author(s): Lu-mei Huang, Li-dong Li, Le Shang, Qing-han Zhou, Juan Lin
      In this study, novel pH-sensitive micelles were prepared from miktoarm star block copolymer, mPEG-b-P(MMA-co-MAA)2, by the atom transfer radical polymerization (ATRP) technique and dialysis method. Molecular structures and characteristics of the micelles were confirmed by 1H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), dynamic light scattering (DLS), and transmission electron microscopy (TEM). The self-assembled micelles have a very low critical micelle concentration, indicating a high colloidal stability in aqueous solution. Methotrexate (MTX) was selected as the model drug of poor solubility. A relatively high drug loading capacity was found, and the in vitro release studies revealed that about 26% of the drug was released in simulated gastric fluid (SGF, pH1.2) over 48h compared to the maximum drug release of about 98% in simulated intestinal fluid (SIF, pH7.4). Thus, the pH-sensitive micelles might serve as promising carriers for oral drug delivery of hydrophobic drugs with controlled release behavior.

      PubDate: 2016-08-20T16:53:27Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.005
      Issue No: Vol. 107 (2016)
       
  • Molecular imprinting of 5-fluorouracil in particles with surface RAFT
           grafted functional brushes
    • Authors: D. Oliveira; C.P. Gomes; R.C.S. Dias; M.R.P.F.N. Costa
      Pages: 35 - 45
      Abstract: Publication date: Available online 28 August 2016
      Source:Reactive and Functional Polymers
      Author(s): D. Oliveira, C.P. Gomes, R.C.S. Dias, M.R.P.F.N. Costa
      Molecularly imprinted particles with surface grafted functional polymer brushes were synthesized and evaluated aiming at the targeting of 5-fluorouracil (5-FU). A molecular imprinting material for 5-FU was prepared through precipitation crosslinking polymerization, in the presence of a RAFT agent, and choosing either methacrylic acid (MAA) or 2-hydroxyethyl methacrylate (HEMA) as functional monomers. In a later step, different kinds of functional polymer brushes, namely poly(methacrylic acid), poly(2-hydroxyethyl methacrylate) and poly(N-isopropylacrylamide) were grafted in the particles through a “grafting from” process starting on the RAFT groups present in their surface. The accomplishment of 5-FU imprinting was proven through comparative drug uptake measurements with imprinted/non-imprinted materials. Enhancement of 5-FU release in alkaline conditions comparatively to acidic environments was shown for particles with different combinations of molecular imprinting and grafted functional brushes. The MAA imprinting system with PMAA grafted functional brushes shows the highest improvement in 5-FU release triggered by a pH change from 2 to 10. Furthermore, for particles with PNIPA grafted brushes, a boost in drug release was also shown at T =20°C as compared to 40°C. The novel achievements reported here put into evidence the combined benefits of molecularly imprinted particles with surface grafted functional polymer brushes concerning molecular recognition and stimulated 5-FU release.

      PubDate: 2016-08-30T17:03:38Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.007
      Issue No: Vol. 107 (2016)
       
  • Poly(lactide-co-glycolide)/cyclodextrin (polyethyleneimine) microspheres
           for controlled delivery of dexamethasone
    • Authors: Sanda Bucatariu; Marieta Constantin; Paolo Ascenzi; Gheorghe Fundueanu
      Pages: 46 - 53
      Abstract: Publication date: Available online 31 August 2016
      Source:Reactive and Functional Polymers
      Author(s): Sanda Bucatariu, Marieta Constantin, Paolo Ascenzi, Gheorghe Fundueanu
      Water-in-oil-in-water (w1/o/w2) solvent evaporation method is a technique for encapsulation and protection of water soluble and chemically sensitive bioactive molecules. One of the most important disadvantages of this method is the diffusion of bioactive molecule, during synthesis, from the primary to the secondary aqueous phase, reducing dramatically the encapsulation yield. Therefore, dexamethasone sodium phosphate (DM), a corticosteroid water soluble drug, which is sensitive to degradation, was first complexed with hydroxypropyl cyclodextrin (HPCD), γ-cyclodextrin (γ-CD) or polyethyleneimine (PEI) and then entrapped in poly(lactic-co-glycolic acid) (PLGA) microspheres obtained by w1/o/w2 solvent evaporation method. Association equilibrium constants for the formation of the HPCD/DM and γ-CD/DM inclusion complexes were also calculated, being 1.420×103 M−1 and 1.447×104 M−1, respectively. PEI was proved to be the most efficient DM trapper, retaining the highest amount of the drug in microspheres, followed by γ-CD and HPCD. Despite the high values of the association equilibrium constants for DM binding to HPCD and γ-CD, both cyclodextrins are not able to protect the drug against UV irradiation. The morphology of the microspheres as well as the drug entrapment efficiency and the release rates are influenced by complexing agents and the ratio between the primary aqueous phase and the organic phase.

      PubDate: 2016-09-03T17:22:32Z
      DOI: 10.1016/j.reactfunctpolym.2016.08.008
      Issue No: Vol. 107 (2016)
       
  • A novel gelatin-AgNPs coating preparing method for fabrication of
           antibacterial and no inflammation inducible coatings on PHBV
    • Authors: Xingxing Zhao; Hairong Liu; Yibing Hu; Jiying Huang; Shuihan Zhang; Fei Ja
      Pages: 54 - 59
      Abstract: Publication date: Available online 25 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Xingxing Zhao, Hairong Liu, Yibing Hu, Jiying Huang, Shuihan Zhang, Fei Ja
      Silver nanoparticles (AgNPs) based antibacterial materials are widely applied to commodity and clinic wound treatments. However, genotoxicity and inflammatory response induced by AgNPs inhibit their application as the antibacterial coating of medical devices like catheters. A novel gelatin-AgNPs coating manufacture method was introduced here to generate an antibacterial coating, which nearly immunes to inflammatory, on basal PHBV material. The novel gelatin-AgNPs coating was produced by immobilizing gelatin on the Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) membrane and subsequently fixing AgNPs on acquired gelatin coating. Prepared gelatin-AgNPs coatings displayed considerable antibacterial capacity. These gelatin-AgNPs coatings did not cause inflammation, growth inhibition or apoptosis to normal human embryonic lung fibroblasts, MRC-5 cells, by analyzing the transcription levels of relevant genes in these cells incubated with tested coatings for 4days. Hence, this novel gelatin-AgNPs coating manufacture method paved its way to apply in medical devices manufacture including catheters.

      PubDate: 2016-07-26T15:54:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.07.014
      Issue No: Vol. 107 (2016)
       
  • Novel phenolic antioxidant-functionalized dendritic polyethylene:
           Synthesis by tailor-made nickel(II) α-diimine-catalyzed copolymerization
           and its characteristics as non-releasing additive
    • Abstract: Publication date: Available online 25 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Zahra Balzadeh, Hassan Arabi
      This work describes a simple one-pot and controlled synthetic method to generate migration-resistant bio-friendly tailor-made antioxidants through dendritic polyethylene (DPE)–sterically hindered phenolic antioxidant (SHPA) copolymerization by coordination polymerization using MAO-activated nickel(II)-α-diimine catalyst. The antioxidant tethering into the polymer chain by chain walking catalysts leads to adjustable copolymer architectures possessing different thermal features. It was found that oxidation induction time could be fine-tuned (from 2 to 36min) by appropriate SHPA content selection and PE altering (from 10 to 0.5bar of gage). Furthermore, the chemical composition analysis of DPE–SHPA copolymer shows 0.6wt% SHPA incorporation (approximately 80% conversion) besides a dendritic architecture, containing 123 branches per 1000 carbon atoms and AFM images resembling semi-spherical topology. The migration resistance of the synthesized copolymers and their application as non-releasing additives are also investigated.

      PubDate: 2016-11-27T14:45:28Z
       
  • Effect of reactive functionalization on properties and degradability of
           poly(lactic acid)/poly(vinyl acetate) nanocomposites with cellulose
           nanocrystals
    • Abstract: Publication date: Available online 15 November 2016
      Source:Reactive and Functional Polymers
      Author(s): M. Minhaz-Ul Haque, Debora Puglia, Elena Fortunati, Mariano Pracella
      Nanocomposites of poly(lactic acid) (PLA) containing cellulose nanocrystals (CNCs) were prepared by dispersion of CNCs in aqueous poly(vinyl acetate) (PVAc) emulsion followed by melt extrusion with PLA. Functionalization of PVAc by radical grafting of glycidyl methacrylate (PVAc-GMA) was carried out during PVAc polymerization by using ammonium cerium (IV) nitrate as the initiator. The morphology, phase interactions, thermal and mechanical properties and degradability in composting of blends (PLA/PVAc, PLA/PVAc-GMA) and nanocomposites (PLA/PVAc/CNC, PLA/PVAc-GMA/CNC) containing 3wt% CNC were examined by FESEM, AFM, FT-IR, DSC and tensile tests. The study of degradability demonstrated that the disintegration rate of PLA/PVAc-GMA/CNC in soil was higher than that of PLA/PVAc/CNC, likely because the epoxy groups of GMA accelerated the biodegradation rate through the formation of radicals.
      Graphical abstract image

      PubDate: 2016-11-21T03:11:01Z
       
  • Amphiphilic block-random copolymer surfactants with tunable
           hydrophilic/hydrophobic balance for preparation of non-aqueous dispersions
           by an emulsion solvent evaporation method
    • Abstract: Publication date: Available online 16 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Naofumi Ezaki, Yoshifumi Watanabe, Hideharu Mori
      The structural effects of amphiphilic block-random copolymers composed of stearyl methacrylate (SMA) and diethanolamine-modified glycidyl methacrylate (DEAGMA), poly(SMA)-b-poly(DEAGMA-r-SMA)s on their surfactant efficacy for a non-aqueous emulsion solvent evaporation method were investigated. Three series of block-random copolymers (i) with different amounts of DEAGMA in the poly(DEAGMA-r-SMA) segment and (ii, iii) with different chain lengths of each segment were synthesized by reversible addition-fragmentation chain transfer polymerization. The surfactant efficacies of these copolymers were investigated in terms of the interfacial tension and modulus, size, and stability of the emulsion and dispersion. Suitable comonomer composition and chain lengths of both segments produced stable emulsions and dispersions with small particle sizes (<200nm).

      PubDate: 2016-11-21T03:11:01Z
       
  • Synthesis and adsorptive characteristics of novel chitosan/graphene oxide
           nanocomposite for dye uptake
    • Abstract: Publication date: Available online 16 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Muhammad Arif Kamal, Saira Bibi, Syeda Wishal Bokhari, Ahmad Hassan Siddique, Tariq Yasin
      A green approach was utilized to synthesize crosslinked chitosan-based graphene oxide (GO) nanocomposite membrane using tetraethyl orthosilicate (TEOS) as a crosslinking agent. The structural analysis of the membranes was investigated using infrared (IR) spectroscopy. The porosity and morphology of membranes were examined using scanning electron microscopy (SEM) and BET (Brunauer–Emmett–Teller) techniques. The SEM micrographs revealed that GO was uniformly mixed in chitosan matrix. BET results further confirmed that the inclusion of GO led to increase the surface area of the nanocomposite which also improved its adsorptive properties. Congo red (CR) dye was used to study the adsorption efficiency of developed membrane. The effect of time, pH and dose rate on the adsorption behavior of developed membrane was investigated. The maximum loading capacity of CR on CS/GO membrane was 175.9mg/g. The kinetics and equilibrium isotherms were well described by pseudo-second-order and Langmuir isotherm models respectively. The high adsorption efficacy and green nature of the nanocomposites provide a good alternative to already existing petroleum based (biostable) membranes.

      PubDate: 2016-11-21T03:11:01Z
       
  • Pb2+ removal from aqueous synthetic solutions by calcium alginate and
           chitosan coated calcium alginate
    • Authors: Noor Edin Mousa; Claudia Maria Simonescu; Rodica-Elena Pătescu; Cristian Onose; Christu Tardei; Daniela C. Culiţă; Ovidiu Oprea; Delia Patroi; Vasile Lavric
      Abstract: Publication date: Available online 10 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Noor Edin Mousa, Claudia Maria Simonescu, Rodica-Elena Pătescu, Cristian Onose, Christu Tardei, Daniela C. Culiţă, Ovidiu Oprea, Delia Patroi, Vasile Lavric
      This research study deals with lead(II)/Pb2+ removal from aqueous solutions by calcium alginate (CA) and chitosan coated calcium alginate (CCCA) as adsorbents, in batch experiments. A simple synthesis method was used to prepare both adsorbent materials. CA and CCCA were characterized using infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TG). The main parameters determining the quantity of lead(II) ions adsorbed are: the initial pH solution, the lead(II)ions initial concentration and the temperature. The experiments revealed that the adsorption capacity, thus, the removal efficiency are higher for CCCA compared to CA. The adsorption of lead(II) ions onto both CA and CCCA materials is an endothermic spontaneous process, as resulted from the thermodynamic experiments. Consequently, a moderate increase of temperature improves the adsorption capacity. The thermodynamic equilibrium sorption experimental data are well fitted by Freundlich adsorption isotherm for both tested adsorbents, better than Langmuir's. Accordingly, lead(II) ions adsorption onto CA and CCCA develops obeying a multilayer mechanism. The kinetic experimental data were fitted by both pseudo-first, and pseudo-second order models. The former approaches better the experimental results for both adsorbents. The mechanism involved in lead removal is a combination between ion-exchange and coordination/chelation based on experimental results.

      PubDate: 2016-11-14T02:52:37Z
      DOI: 10.1016/j.reactfunctpolym.2016.11.001
       
  • Synthesis of curcumin/polyrhodanine nanocapsules with antimicrobial
           properties by oxidative polymerization using the Fenton reaction
    • Authors: Jun-Won Kook; Soyeon Kim; Jun-Young Lee; Jung-Hyun Kim
      Abstract: Publication date: Available online 3 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Jun-Won Kook, Soyeon Kim, Jun-Young Lee, Jung-Hyun Kim
      Curcumin exhibits various biological activities; however, its applications are limited because of its poor water solubility. In this study, we describe an encapsulation process that improves this property using a polyrhodanine shell material synthesized by oxidative polymerization. Unlike the previous methods of oxidative polymerizations, we used the Fenton reaction to introduce a FeCl3/H2O2 combination system. By changing the rhodanine monomer ratio, the curcumin/polyrhodanine nanocapsule (CPR-NC) shell thickness could be controlled. The release behavior of curcumin was characterized by UV–Vis spectroscopy over time. Antimicrobial tests with curcumin, polyrhodanine, and CPR-NC were performed to analyze the minimum inhibitory concentration and inhibition zones.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.016
       
  • Surface molecularly imprinted organic-inorganic polymers having affinity
           sites for cholesterol
    • Authors: Irina Polyakova; Ludmila Borovikova; Aleksandra Osipenko; Elena Vlasova; Boris Volchek; Oleg Pisarev
      Abstract: Publication date: Available online 3 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Irina Polyakova, Ludmila Borovikova, Aleksandra Osipenko, Elena Vlasova, Boris Volchek, Oleg Pisarev
      Novel granular organic-inorganic molecularly imprinted polymers (MIPs) based on 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) were prepared by co-polymerization on the surface of selenium (Se) nanoparticles stabilized with poly(vinyl pyrrolidone) (PVP) at different concentrations of cholesterol as a template molecule. The synthesis occurred in Pickering microemulsion. The obtained compounds are intended for use as selective hemosorbents in efferent therapy of hypercholesterolemia. The sorbents were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and sorption experiments. It was revealed that MIPs possess more pronounced porous structure as compared to that of the reference non-imprinted polymer (NIP). The influence of the amount of introduced cholesterol template on physico-chemical and sorption properties of MIPs was investigated. FTIR spectroscopy and thermodynamic studies showed that the affinity of MIPs towards cholesterol is related to multi-point polyfunctional binding of adsorbate in complementary cavities or imprint sites; hydrogen bonds play the key role in recognition of the target molecule. The Langmuir, Freundlich, Temkin and BET model isotherms were used for interpreting the experimental data on the equilibrium sorption experiments. The maximum adsorption capacities increased for the MIP synthesized at the highest molar concentration of the template. Cholesterol adsorption proceeded in the monolayer within a wide concentration range, and the data obtained in these experiments better conformed to the Langmuir isotherm. Formation of the surface sorption layer in the MIPs facilitates availability of imprint sites and enhances the efficiency of specific cholesterol binding from blood plasma in vitro.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.010
       
  • Synthesis and chiroptical properties of novel helical polyacetylenes
           containing fluorene pendant groups in the side chains
    • Authors: Yuping Liu; Shujing Li; Qingzhong Zhang; Jing Zhang; Chunping Du; Wei Huang
      Abstract: Publication date: Available online 2 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Yuping Liu, Shujing Li, Qingzhong Zhang, Jing Zhang, Chunping Du, Wei Huang
      A series of novel substituted acetylene monomers bearing fluorene pendant groups (C13H9COCH2CH2CO-R-CH2C≡CH, R=NH (IV 1 ), R=O (IV 2 ), R=NHCH(CH3)CONH (IV 3 ), R=NHCH(CH3)COO (IV 4 )) have been synthesized and subsequently polymerized with [Rh(nbd)Cl]2 as a catalyst to obtain the corresponding polyacetylenes (Poly(IV 1–4 )). The 1H NMR spectra demonstrated that all the obtained polyacetylenes had high cis-stereoregular structures. The results of CD (circular dichroism) and UV–vis spectra showed that Poly(IV 3,4 ) took a tight helical structure, while Poly(IV 1,2 ) did not. The chiral amino acid units in the side chains of Poly(IV 3,4 ) induced the main chain to form the helical conformation. In addition, owing to the large steric repulsion and π-π interaction between the bulky fluorene groups, Poly(IV 3,4 ) showed good helical stability at various temperatures (−10–60°C) and in strong polar solvents. Especially, the CD intensity of Poly(IV 3 ) was enhanced with increasing the solvent polarity. Moreover, Poly(IV 1–4 ) also showed good photoluminescent (PL) properties. The nonconjugated aliphatic spacer and the twisting of the polymer main chain were favorable to improve the PL efficiency.

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.015
       
  • Au (III) Uptake by Triazine Polyamine Polymers: Mechanism, Kinetic and
           Equilibrium Studies
    • Authors: Mustafa Can; Melek Doğan; Mustafa İmamoğlu; Mustafa Arslan
      Abstract: Publication date: Available online 3 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Mustafa Can, Melek Doğan, Mustafa İmamoğlu, Mustafa Arslan
      Triazine-polyamine polymers were successfully synthesized and adsorption of the gold (III) ions from chloride-containing solutions was carried out by comparing the effect of amine chain lengths in the polymers triazine-ethylenediamine (EDA), triazine-triethylenetetramine (TETA) and triazine-pentaethylene hexamine (PEHA). The second-order kinetic equation provides the best correlation for the adsorption process. Langmuir equation has a good fit for all the adsorption systems. Langmuir monolayer adsorption capacities of the EDA, TETA and PEHA polymers were 548, 1003 and 1086mg/g, respectively. Adsorption mechanism was determined using FTIR, XPS, SEM, SEM Mapping and EDS. Adsorption mechanism is followed by ionic and surface complex formation mechanisms. Hydroxy chloro gold complexes were more interacted with nitrogen atoms of amine groups in polymers than nitrogen atoms in triazine rings. The adsorption capacity did not decrease after using all polymers five times. Furthermore, elution of the adsorbed Au (III) ions was made easily using 3% (m/v) thiourea solution in 1M HCl. From the results, it was concluded that EDA, TETA and PEHA polymers have a high gold uptake capacity and are highly efficient for the recycling of gold.
      Graphical abstract image

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.009
       
  • Bionanostructure-catalyzed one-pot three-component synthesis of
           3,4-dihydropyrimidin-2(1H)-one derivatives under solvent-free conditions
    • Authors: Ali Maleki; Reza Paydar
      Abstract: Publication date: Available online 4 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Ali Maleki, Reza Paydar
      In this work, chitosan/graphene oxide as a green bionanocomposite catalyst was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR) spectra, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis, atomic force microscopy (AFM) and scanning electron microscopy (SEM) images. Then, it was used as a nanocatalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives by a one-pot three-component condensation reaction of benzaldehyde, 1,3-ketoesters and urea in excellent yields and short reaction times under solvent-free conditions. The reaction work-up was simple and the catalyst could easily be separated from the reaction mixture and reused in subsequent reactions.
      Graphical abstract image

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.013
       
  • Adsorption of As (V) by poly (N-octyl-4-vinylpyridinium) bromide:
           Determination of As (V) by direct measurement of fluorescence on the solid
           phase
    • Authors: Javier González-Navarrete; María Inés Toral; Angel Leiva; Mehrdad Yazdani-Pedram; Hernán E. Ríos; Ximena Briones-Olarán; Marcela D. Urzúa
      Abstract: Publication date: Available online 2 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Javier González-Navarrete, María Inés Toral, Angel Leiva, Mehrdad Yazdani-Pedram, Hernán E. Ríos, Ximena Briones-Olarán, Marcela D. Urzúa
      Adsorption of As (V) by poly (N-octyl-4-vinylpyridinium) bromide (P4VPyC8), used as solid phase, was studied. Determination of As (V) was carried out by direct measurement of the fluorescence intensity on the solid phase. Adsorption variables were optimized for obtaining optimum values of pH and agitation time, where pH9.0 and 60min were established as optimum values. The adsorption of arsenic (V) was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It was found that the fluorescence of the solid phase increases as the concentration of arsenic increases. Linearity was observed in the concentration range 6.80 to 90.0μgL−1. The detection limit for determination of As (V) by this method was 2.24μgL−1 and the relative standard deviation (RSD) was 1.72%. The amount of retained As (V) was 0.154mg/g of solid phase. The determination of As (V) in a sample of tap water by this method was well compared with the value reported by an external certified laboratory. Therefore, the method of analysis proposed here could be used as a screening methodology for monitoring the fulfillment of the norm for arsenic concentration in tap water.
      Graphical abstract image

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.011
       
  • Soft-nanocoupling between silica and gold nanoparticles based on block
           copolymer
    • Authors: Qian Zhang; Shuhuan Yang; Tingting Zhu; Jung Kwon Oh; Pengfei Li
      Abstract: Publication date: Available online 5 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Qian Zhang, Shuhuan Yang, Tingting Zhu, Jung Kwon Oh, Pengfei Li
      A novel triblock copolymer of ABC type was synthesized by RAFT polymerization with good control and successfully acts as a specific “adhesive” to “glue” the SiO2 nanoparticles (NPs) and Au NPs together to make a hybrid. This method, with the coined name, soft-nanocoupling, is based on specific anchoring of organic groups onto the surface of inorganic nanoparticles with all-covalent interactions. SiO2 and Au NPs were used as a proof of concept in this contribution. For the triblock copolymer, namely POE-PGMA-PMPS {poly[oligo(ethylene oxide) methyl ether metharylate]-b-polyglycidyl methacrylate-b-poly[3-(methacryloxypropyl) trimethoxysilane]}, the POE block with oligo-PEG side chains was used to improve the dispersability in solvent media; the PGMA block that was further reacted with lipoic acid was used to anchor onto the Au NPs; and the silane-containing PMPS block can “grab” the SiO2 NPs. It was found that the resulting SiO2-Au hybrid has a corona shell of SiO2 NPs with Au NPs tightly embedded inside, and can even tolerate a harsh sonication process of 1h. Since the soft triblock copolymer functions as a bridge to couple Au and SiO2 NPs together, the process is called soft-nanocoupling. Compared to the conventional hard-coupling process, which requires specific case by case procedures, soft-nanocoupling is more straightforward, and especially can be designed in a modular way depending on the specific NPs used. With the well-established synthetic methodologies of NPs of single components to date, such as SiO2, Au, FexOy etc., all that is needed to make hybrid NPs is the proper design of a specific “glue” with anchoring moieties targeting the selected NPs. Thus, the soft-nanocoupling methodology affords a new platform for fabricating hybrid nano-objects from NPs using block copolymers.
      Graphical abstract image

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.012
       
  • Functionalization of 2-hydroxyethyl methacrylate-based polyHIPEs: Effect
           of the leaving group
    • Authors: Janja Majer; Muzafera Paljevac; Ema Žagar; Sebastijan Kovačič; Peter Krajnc
      Abstract: Publication date: Available online 1 November 2016
      Source:Reactive and Functional Polymers
      Author(s): Janja Majer, Muzafera Paljevac, Ema Žagar, Sebastijan Kovačič, Peter Krajnc
      Highly porous polymers based on 2-hydroxyethyl methacrylate (HEMA) have been successfully prepared through the high internal phase oil-in-water emulsions and further functionalized. Since functionalization of alcohol containing polymers through the direct nucleophilic substitution is rather difficult due to poor leaving ability of hydroxyl groups, the HEMA-based polymers have been modified through the halodehydroxylation and tosylation in order to obtain better leaving group residues as compared to the hydroxyl one. Conversion of hydroxyl groups into the corresponding alkyl halides and tosylates were found to be 78, 50, and 36% for the HEMA-Cl, HEMA-Br and HEMA-Ts, respectively. Further functionalization with the piperazine and tris(2-aminoethyl)amine through amine-alkylation was performed to test the leaving group ability of previously modified HEMA-Cl, HEMA-Br and HEMA-Ts polymers. Lower conversion rates for the HEMA-Cl or the HEMA-Br (between 18 and 41%) were found as compared to the HEMA-Ts (between 46 and 89%).

      PubDate: 2016-11-06T21:51:07Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.008
       
  • Improving the Hydrolytic Stability of Aryl Cyanate Esters by Examining the
           Effects of Extreme Environments on Polycyanurate Copolymers
    • Authors: Alasdair O. Crawford; Gabriel Cavalli; Brendan J. Howlin; Ian Hamerton
      Abstract: Publication date: Available online 29 October 2016
      Source:Reactive and Functional Polymers
      Author(s): Alasdair O. Crawford, Gabriel Cavalli, Brendan J. Howlin, Ian Hamerton
      Three cyanate ester monomer or oligomer species: 2,2-bis(4-cyanatophenyl)propane 1, 1-1-bis(4-dicyanatophenyl)ethane 2, and the oligomeric phenolic cyanate 3, are blended in various ratios to form binary mixtures (18 in total), formulated with copper(II) acetylacetonate (200 ppm) in dodecylphenol (1 % w/v active copper suspension) and cured (3 Kmin−1 to 150 °C + 1 hour; 3 Kmin−1 to 200 °C + 3 hours) followed by a post cure (3 Kmin−1 to 260 °C + 1 hour). Cured copolymers were exposed to environments of elevated relative humidity (75 % RH) and parallel immersion testing in H2O, H2SO4 (10 %) and NaOH (10 %) at 25 °C for a period of up to 2 years and accelerated ageing in boiling water (14 days). Periodic measurements are made of moisture gain along with infrared spectra and compared with cured homopolymers. Changes in mass are recorded periodically throughout exposure, prior to destructive thermo-mechanical analyses. Dynamic mechanical thermal analysis data comparing neat and exposed blends demonstrate the detrimental effect of moisture ingress whilst data from thermogravimetric analysis demonstrate no change in degradation onset between neat and exposed materials. An optimised blend of 1:1 of monomer units 1 and 2 was found to absorb less moisture than blends of different stoichiometry or between other respective monomeric units, consequently limiting the deleterious effect of moisture ingress.
      Graphical abstract image

      PubDate: 2016-10-30T21:45:44Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.007
       
  • Preparation of poly(glycolide-co-lactide)s through a green process:
           Analysis of structural, thermal, and barrier properties
    • Authors: Giuliana Gorrasi; Angelo Meduri; Paola Rizzarelli; Sabrina Carroccio; Giusy Curcuruto; Claudio Pellecchia; Daniela Pappalardo
      Abstract: Publication date: Available online 10 October 2016
      Source:Reactive and Functional Polymers
      Author(s): Giuliana Gorrasi, Angelo Meduri, Paola Rizzarelli, Sabrina Carroccio, Giusy Curcuruto, Claudio Pellecchia, Daniela Pappalardo
      We have successfully synthesized poly(lactide), poly(glycolide), and poly(lactide-co-glycolide) copolymers in bulk by ring-opening homo- and copolymerization of glycolide and L-lactide, using sodium hydride as the environmentally friendly and nontoxic initiator. Random copolymers were obtained, and the microstructure was characterized by nuclear magnetic resonance (1H and 13C NMR) and matrix-assisted laser desorption ionization mass spectrometry (MALDI MS). The mechanism of reaction was elucidated by analysis of the polymer end groups. Homopolymer and copolymers films and their blends were obtained, and their structure and physical properties were analyzed. Thermal degradation analysis showed superior characteristics of copolymers with respect to the blends. Transport properties of water vapor were also evaluated and correlated to the copolymer composition.

      PubDate: 2016-10-16T23:31:06Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.002
       
  • Preparation of small and photoresponsive polymer nanoparticles by
           intramolecular crosslinking of reactive star azo-polymers
    • Authors: Liang Ding; Chengshuang Wang; Ruiyu Jiang; Lingfang Wang; Wei Song
      Abstract: Publication date: Available online 14 October 2016
      Source:Reactive and Functional Polymers
      Author(s): Liang Ding, Chengshuang Wang, Ruiyu Jiang, Lingfang Wang, Wei Song
      Four-arm star azo-polymers with molecular weight control are prepared using the high selectivity of olefin cross-metathesis between acrylates and terminal olefins in the presence of multifunctional acrylates as the selective chain transfer agent. These reactive star azo-polymers are readily converted, by two different intramolecular crosslinking reactions of the end acrylate groups in dilute solution, to the new types of polymeric nanoparticles that exhibit distinct photoresponsive performance. Furthermore, the size and morphology of two types of polymeric nanoparticles show interesting and circular transformations when azo chromophore in nanoparticles underwent trans–cis–trans or cis–trans–cis isomerization cycles.
      Graphical abstract image

      PubDate: 2016-10-16T23:31:06Z
      DOI: 10.1016/j.reactfunctpolym.2016.10.004
       
  • Dissociation properties and behavior of active humic fractions dissolved
           in aqueous systems
    • Authors: Martina
      Abstract: Publication date: Available online 23 September 2016
      Source:Reactive and Functional Polymers
      Author(s): Martina Klučáková
      The function of humic acids in nature is strongly affected by their solubility and their ability to dissociate. This work is focused on the fraction of humic acids which is dissolved in water or rather the aqueous phase in humic-containing systems. This fraction can be rich in acidic functional groups which are the most active ones. The amount of the dissolved humic fraction can be considered to be the result of equilibrium between dissolved and undissolved humic substances. In this study, the concentration dependence of the dissociation constants was determined and analyzed. A maximum was observed for the dependence of the degree of dissociation on the concentration. In less concentrated leachates, less soluble humic particles with weaker functional groups were able to be dissolved. The weak functional groups have lower dissociation ability and they were able to remain in non-dissociated forms. The increase of humic contents in leachates caused smaller amounts of soluble fractions with the weakest functional groups to remain in an undissolved form, which led to the increase in the degree of dissociation. The increase in concentration of humic acids in the leachates caused the degree of dissociation decrease as a result of interactions between dissolved particles.

      PubDate: 2016-09-26T04:08:54Z
       
 
 
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